staticboolTryParse(string s,outint num){
if(!string.IsNullOrWhiteSpace(s)){
num =0;returnfalse;}int result =0;bool minus = s[0]=='-'?true:false;if(minus && s.Length ==1){
num =0;returnfalse;}for(int i = minus ?1:0; i < s.Length; i++){
if(s[i]>='0'&& s[i]<='9'){
result = s[i]-48+ result *10;}else{
num =0;returnfalse;}}
num = minus ?-result : result;returntrue;}